1. Field of the Invention
The present invention relates to a technical field of an electrical power transmission and distribution, in particular to an automatic three-phase unbalanced load compensation experimental device and its control method.
2. The Prior Arts
Three-phase load unbalance has many adverse effects on power system. At present, people have done much research on three-phase unbalanced load compensation of the electrical power transmission and distribution system, focusing on the design of the reactive power compensation device body and the control strategies and methods of the reactive power compensation device. Due to lots of restrictive conditions, many advanced algorithms and control strategies are still deduced theoretically and simulated by the computer, and a few can be tested in site with much preparation and high cost. Therefore, a general, automatic three-phase unbalanced load compensation experimental platform is applicable to the test of various unbalanced load compensation strategies, and this experimental platform only can perform its function when there is a loading device. Reactive power compensation mainly aims at loads such as electric arc furnace, electric welding machine, electrified railway, etc. in industry. These loads can cause reactive power impact on the system in a short time, which causes serious three-phase unbalance of the system. When this type of load is simulated on the experimental platform, load variation must be controlled quickly and accurately. At the same time, lots of single-phase electrical equipment in the power system have strong randomness and uncertainty, so a load simulation experimental device which can connect/disconnect inductive load, capacitive load and resistive load in various topologies into/from the system quickly and accurately have great practical significance.